Badiorepbodtjcer



Dec. 20, 1927.

W. L. ECKHARDT RADIO REPRODUCER Filed July 9, 1926 I INVENTOR. 4

' ATTORNEY. I n

Patented Dec. 20, 1927.

UNITED STATES PTENT OFFICE.

WALTER L. ECKI-IARDT, F PHILADELPHIA, PENNSYLVANIA.

RADIOREPBODUGER.

Application filed July 9, 1926. Serial Ito. 121,350.

This invention relates to, radio reproof the drum-shaped portion of the resonant ducers and it has for its general object to member; and provide a novel construction of reproducer Fig. 4 is a view in section of the apexial including means whereby a more accurate portion of the diaphragm, the said section reproduction of sounds, whether musical or being taken in a plane coincident or-parallel otherwise, is effect-ed than has heretofore with the axis of the said diaphragm and the been practical. parts illustrated being shown in spaced re- It also is an object 01" the invention to lation with. respect to eachotherready to provide a reproducer of novel construction be assembled.

including a plurality of independent vibra- Referring, to the drawing, 1 designates a tory elements adapted to be arranged and base of relatively large dimensions upon united in such relation to each other that which is mounted a pedestal-like portion 2 they cooperate to'reproduce accurately the upon which the drum-shaped portion 3 of various modulations of vibrations due to the resonant member is mounted. Both of 15 sound waves, whether the sound be musical the parts 1 and 2 preferably consist ofswood.

or of any other character. The drum-shaped portion3 preferably con- A further object of the invention is to sists of wood which may be built up of thin provide a radio reproducer comprising a sheets, in. known manner. Mounted within plurality of independent but operatively rethe drum-shaped portion 3 at one end is a 20 lated conical members mounted within and wooden sheet 1 constituting a sounding cooperating with a resonant member to acboard for the reproducer. The sheet 4.- is curately reproduce sounds, musical or otherseated against an inner rim 5 mounted withwise. y in the drum-shaped portion 3 adjacent one Another object of the invention is to proend thereof. The sounding board sheet d 25 vide a central conical floating vibratory isprovided with a central opening 6, as

member surrounded by a plurality of simishown in Fig. 2 of the. drawing. 7 lar conical vibratory members, the latter The opposite end of the portion 3 is probeing connected with the former and also vided with a closure .10 of suitable fabric having connection with and being suppo1t provided at its periphery with a wirerim 30 ed upon a resonant member, preferably of 11, by means of which the closure 10 is held drum-shape. in place within the portion 3 against an 'TO these and other ends the invention inner rim 12, in known manner, comprehends the construction and arrange- The vibratory diaphragm comprises a ment of parts as hereinafter described in. central conical vibratory member 15 which 35 detail, particularly pointed out in the is surrounded by a plurality of relatively claims and as illustrated in the acoompa-nysmall, conical members 16. The latter, in

ing drawing, in which I have illustrated one the construction shown, are located in conform of a convenient embO imQH of h tact with each other and are fastened to invention. gether at their outer adjoining edges by 40 In the drawing: means of clips 17 and they are also fas- Fig. 1 is a view in fron eleva ion f a 'tened at the inner sides of their outer ends reproducer embodying the invention, with by means of clips 18 to the outer end of the closure mounted within the end of the the central conical member 15 with which drum-shaped portion of the reson n emthey are in Contact. The several vibratory 45 her-removed; conical members 15 and 16converg'e from' Fig. 2 is a central vertical sectional vlew an intermediatereg on of the portion 3 of of the said r-eproducer; the resonant member toward one end ofthe Fig. 3 is a view in rear elevation of a latter and toward the axis thereof. The vifragmentary portion of the diaphragm and bratory conical members 16 are each PXOVld.

ed with narrow extensions or tabs 20 at their outer ends and at'their outer sides which are seated against the inclined edge surface 21 of the rim 22 mounted within the portion 3 in a plane intermediate the opposite ends of the said portion.

In the construction shown, the said rim is located about midway between the opposite ends of the said portion. The tabs or extensions 20 may be secured to the inclined edge surface of the rim 22 by means of a suitable glue or cement, or otherwise, as may be preferred. The outer ends of the vibratory conical members 16 are connected, as already stated, to the outer end portion of the vibratory conical member 15 by means of clips 18.

The small convergent ends of the vibra tory conical members 15 and 16 are secured together by means of conicalshaped binding members 23 ant 2d, the former being located within the end of the conical member 15, while the latter is located outside of the convergent ends of the conical member 16. The members 23 and 2t are provided with holes 25 extending therethrough in alinement with the axes thereof, as shown. The members 23 and 2 are placed in. position, as indicated in Figs. 2 and d, and the oles therethrough are coincident with a hole 26 extending through the small end of the conical member 15. A headed fastening member 28 extends through the said holes and the convergentsmall ends of the conical member 16 rest against the said member 28 .underneath the head thereof, as is clearly indicated in Fig. 2 of the drawing; The convergent small end portions of the conical vibratory members 16 and the walls of the small end portion of the conical member 15 are bound and held between the clamping members 23 and 24. The clamping and holding action of the said members is effected by means of the headed holding member 28. The clamping action is effected by means of a nut 30 which engages the screw-threaded inner end of the said holding member 28. lVhen the said nut is tightened the members 23 and 2d are drawn together and clamping action thereof operates to flatten the small end portions of the vibratory conical members 16, as is clearly shown in Fig. 2 of'the drawing. i

The small end portion of the diaphragm projects through the opening 6 in the sounding board 4:, as shown in Fig. 2. The bolding member 28 is provided with an axial hole extending therethrough within which one end of a reed 32 is fastened by means of a binding screw 33. The opposite end of the said reed 32 is connected to the vibratory element, not shown, of a loud speaker unit 35 mounted upon a bar 36 which extends diametrally of the portion 3 of the resonant member. The said bar 36 is secured at its opposite ends to the rim 22, previously referred to. Current is supplied to the loud speaker unit 35 by means of a conductor 37.

In the operation of the reproducer the vibratory element of the loud speaker unit- 35 is placed in vibration under the influence of the waves due to musical sounds or sounds of other character and these vibrations are transmitted through the reed 32 to the conical vibratory members 15 and 16. The latter members are thereby caused to vibrate and the ibrations thus produced are transmitted to the resonant member or unit of the structure by which amplification is effected.

The cone-shaped vibratory members to a certain extent are independent of each; other and may consist of sheets of material of different thicknesses. In consequence of this a reproducer maybe constructed in which the vibratory diaphragm thereof is particularly adapted for the reception of sounds having certain characteristic tonal qualities. The diaphragm is of multiplex character and consequently may be so constructed as to meet the needs and requirements for reproducing musical compositions having different characteristic qualities.

The vibratory motions of the conical members 15 and 16 are transmitted to the resonant member including the drum-shaped portion 3 and the sounding board 4;. As a result of the spaces between the conical members 16 and the conical member 15 and be tween the said conical members and the drum-shaped portion 3 of the resonantmember means is provided whereby the sound vibrations emanating from the sounding board 4: are permitted to move readily pastthe said conical members 15 and 16 constituting the vibratory diaphragm of-the structure.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: i

1. In a radio reproducer, the combination of a resonant member comprising a drum shaped portion and a sounding board secured thereto, a plurality of hollow concshaped members mounted upon the said drum-shaped portion and radiating from a point adjacent the center of the said sounding board toward the opposite end of the said drum-shaped portion.

2. In a radio reproducer, the combination of a resonant member comprising a drumshaped portion and av sounding board secured to one end thereof, a diaphragm mounted within the said drum-shaped portion, said diaphragm consisting of a plurality of. hollow cone-shaped members, and means for connecting the said diaphragm to the said drum-shaped portion in a plane. located about midway between the opposite ends of the said drum-shaped portion.

3. A. radio reproducer comprising, in combination, a diaphragm consisting of a central hollow cone-shaped member, a series of hollow cone-shaped members surrounding the said central cone-shaped member and having connection therewith, a drum-shaped member surrounding the said diaphragm, and means for mounting the said series of cone-shaped members upon. the said drumshaped member.

4. A radio reproducer comprising a dia phragm including a floating central holloW conical member and a series of hollow conical members arranged in concentric relation to the said floating hollow conical member.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this 2nd day of July A. 1)., 1926.

WALTER L. EGKHARDT. 

